https://gcc.gnu.org/g:d1d7ecfbc6d86f660ec79ca272b20aea9d6c3ca7
commit r16-3250-gd1d7ecfbc6d86f660ec79ca272b20aea9d6c3ca7
Author: Xi Ruoyao <xry...@xry111.site>
Date: Sat Mar 1 11:46:43 2025 +0800
LoongArch: Don't use "+" for atomic_{load, store} "m" constraint
Atomic load does not modify the memory. Atomic store does not read the
memory, thus we can use "=" instead.
gcc/ChangeLog:
* config/loongarch/sync.md (atomic_load<mode>): Remove "+" for
the memory operand.
(atomic_store<mode>): Use "=" instead of "+" for the memory
operand.
Diff:
---
gcc/config/loongarch/sync.md | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/gcc/config/loongarch/sync.md b/gcc/config/loongarch/sync.md
index f712c2fe07e2..63929abba457 100644
--- a/gcc/config/loongarch/sync.md
+++ b/gcc/config/loongarch/sync.md
@@ -102,7 +102,7 @@
(define_insn "atomic_load<mode>"
[(set (match_operand:QHWD 0 "register_operand" "=r")
(unspec_volatile:QHWD
- [(match_operand:QHWD 1 "memory_operand" "+m")
+ [(match_operand:QHWD 1 "memory_operand" "m")
(match_operand:SI 2 "const_int_operand")] ;;
model
UNSPEC_ATOMIC_LOAD))]
""
@@ -139,7 +139,7 @@
;; Implement atomic stores with amoswap. Fall back to fences for atomic loads.
(define_insn "atomic_store<mode>"
- [(set (match_operand:QHWD 0 "memory_operand" "+m")
+ [(set (match_operand:QHWD 0 "memory_operand" "=m")
(unspec_volatile:QHWD
[(match_operand:QHWD 1 "reg_or_0_operand" "rJ")
(match_operand:SI 2 "const_int_operand")] ;; model
